B.R.H. Van den Bergh

Self-reported symptoms of depressed mood, trait anxiety and aggressive behavior in post-pubertal adolescents: Associations with diurnal cortisol profiles

The association between self-reported symptoms and diurnal cortisol profiles was studied in post-puberty adolescents (29 boys and 29 girls, M(age)=15.06 years). The adolescents completed the Childrens Depression Inventory, State Trait Anxiety Inventory, and an Aggressive behavior scale. The diurnal cortisol profile was derived from three saliva samples, collected at awakening, noon and evening on a week-end day. Univariate repeated measurement regressions revealed that depressed mood and trait anxiety were strongly and aggressive behavior was weakly related to the diurnal cortisol profile: greater emotional distress was associated with flatter diurnal cortisol profiles. Multivariate analysis, however, revealed that only trait anxiety made an independent contribution. Further analyses suggested that trait anxiety was related to elevated evening cortisol rather than to decreased awakening cortisol and that from a trait anxiety score of 38 onwards, high anxious adolescents show clearly higher evening cortisol than low anxious adolescents. These data suggest that anxiety disorder co-morbidity might explain some of the differences in HPA-axis function among depressed patients.

Diurnal cortisol profiles and evening cortisol in post-pubertal adolescents scoring high on the Children's Depression Inventory

Early-onset mood disorders have become a significant public health problem in recent years. The Childrens Depression Inventory (CDI) is a commonly used self-report measure. We studied the relation of CDI cut-offs to biological markers of depression such as the diurnal cortisol rhythm and evening cortisol. In 58 post-pubertal adolescents (29 boys and 29 girls, M(age)=15.1 years), the diurnal cortisol profile was derived from three saliva samples, collected at awakening, at noon and in the evening on a week-end day. Longitudinal repeated measurements regression revealed that the group with CDI>18 (high depressive symptoms) clearly had a higher and flatter diurnal rhythm with elevated evening cortisol compared to either the group with CDI between 13 and 18 (moderate depressive symptoms) or CDI<13 (low depressive symptoms). Multinomial logistic regression indicated that evening cortisol was useful in classifying the adolescents in the high depressive symptoms group, while awakening and noon cortisol were not. Our results indicate that the type of high flattened profiles sometimes seen in individuals who are clinically depressed according to diagnostic interviews can also be identified with a self-report inventory, at high levels of symptom reporting. Given the complexity of conducting diagnostic interviews, this result bears clinical relevance.

A smart wearable textile array system for biomedical telemetry applications

A smart wearable textile array system (SWTAS) with direction of arrival (DoA) estimation and beamforming is proposed and developed for biomedical telemetry applications. This conformal system enables effective and continuous patient monitoring when combined with one or more health sensors, as information about the subjects health condition is received adaptively to guarantee link reliability. This operation is facilitated by a receiver front-end and a digital baseband beamforming network, which enables scalability and flexibility. The proposed SWTAS also features flexible antenna arrays made using textiles, which are arbitrarily located on a cylindrically shaped body phantom to ensure wide spatial DoA estimation capability. Besides being designed to suit on-body placement, the system performance is also characterized for on-body usage using a commercial body-emulating liquid, and placed at a realistic distance from the body, considering user clothing. Investigation indicated a good performance in the systems ±80° forward plane with a DoA accuracy of 3° . Finally, a practical evaluation is presented using two transmitters placed at distinct locations and distances. The system successfully estimated both DoAs and received the telemetry signals using beamforming.

Assessment of Pain Expression in Infant Cry Signals Using Empirical Mode Decomposition

BACKGROUND The presence of decoupling, i.e. the absence of coupling between fundamental frequency variation and intensity contour during phonetic crying, and its extent, reflects the degree of maturation of the central nervous system. OBJECTIVES The aim of this work was to evaluate whether Empirical Mode Decomposition (EMD) is a suitable technique for analyzing infant cries. We hereby wanted to assess the existence and extent of decoupling in term neonates and whether an association between decoupling (derived from EMD) and clinical pain expression could be unveiled. METHODS To assess decoupling in healthy term neonates during procedural pain, 24 newborns were videotaped and crying was recorded during venous blood sampling. Besides acoustic analysis, pain expression was quantified based on the Modified Behavioral Pain Scale (MBPS). Fundamental frequency and the intensity contour of the cry signals were extracted by applying the EMD to the data, and the correlation between the two was studied. RESULTS Based on data collected in healthy term neonates, correlation coefficients varied between 0.39 and 0.83. The degree of decoupling displayed extended variability between the neonates and also in different cry bouts in a crying sequence within an individual neonate. CONCLUSION When considering the individual ratio between the mean correlation of cry bouts during a crying sequence and their standard deviation, there seems to be a positive trend with increasing MBPS value. This might indicate that higher stressed subjects have less consistency in the investigated acoustic cry features, concluding that EMD has potential in the assessment of infant cry analysis.

Multimodal processing of emotional information in 9-month-old infants II: Prenatal exposure to maternal anxiety

The ability to read emotional expressions from human face and voice is an important skill in our day-to-day interactions with others. How this ability develops may be influenced by atypical experiences early in life. Here, we investigated multimodal processing of fearful and happy face/voice pairs in 9-month-olds prenatally exposed to maternal anxiety, using event-related potentials (ERPs). Infants were presented with emotional vocalisations (happy/fearful) preceded by emotional facial expressions (happy/fearful). The results revealed larger P350 amplitudes in response to fearful vocalisations when infants had been exposed to higher levels of anxiety, regardless of the type of visual prime, which may indicate increased attention to fearful vocalisations. A trend for a positive association between P150 amplitudes and maternal anxiety scores during pregnancy may suggest these infants are more easily aroused by and extract features more thoroughly from fearful vocalisations as well. These findings are compatible with the hypothesis that prenatal exposure to maternal anxiety is related to more extensive processing of fear-related stimuli.

Multimodal processing of emotional information in 9-month-old infants I: emotional faces and voices

Making sense of emotions manifesting in human voice is an important social skill which is influenced by emotions in other modalities, such as that of the corresponding face. Although processing emotional information from voices and faces simultaneously has been studied in adults, little is known about the neural mechanisms underlying the development of this ability in infancy. Here we investigated multimodal processing of fearful and happy face/voice pairs using event-related potential (ERP) measures in a group of 84 9-month-olds. Infants were presented with emotional vocalisations (fearful/happy) preceded by the same or a different facial expression (fearful/happy). The ERP data revealed that the processing of emotional information appearing in human voice was modulated by the emotional expression appearing on the corresponding face: Infants responded with larger auditory ERPs after fearful compared to happy facial primes. This finding suggests that infants dedicate more processing capacities to potentially threatening than to non-threatening stimuli.

Anxious women do not show the expected decrease in cardiovascular stress responsiveness as pregnancy advances.

Altered stress responsiveness is a risk factor for mental and physical illness. In non-pregnant populations, it is well-known that anxiety can alter the physiological regulation of stress reactivity. Characterization of corresponding risks for pregnant women and their offspring requires greater understanding of how stress reactivity and recovery are influenced by pregnancy and womens anxiety feelings. In the current study, women were presented repeatedly with mental arithmetic stress tasks in the first and third pregnancy trimester and reported their trait anxiety using the state trait anxiety inventory. Cardiovascular stress reactivity in late pregnancy was lower than reactivity in the first pregnancy trimester (heart rate (HR): t(197)=4.98, p<.001; high frequency heart rate variability (HF HRV): t(196)=-2.09, p=.04). Less attenuation of stress reactivity occurred in more anxious women (HR: b=0.15, SE=0.06, p=.008; HF HRV: b=-10.97, SE=4.79, p=.02). The study design did not allow the influence of habituation to repeated stress task exposure to be assessed separately from the influence of pregnancy progression. Although this is a limitation, the clear differences between anxious and non-anxious pregnant women are important, regardless of the extent to which differing habituation between the groups is responsible. Less dampened stress reactivity through pregnancy may pose long-term risks for anxious women and their offspring. Follow-up studies are required to determine these risks.